1. Field of the Invention
The present invention relates to convenience copiers and reproduction apparatus. More specifically, the invention relates to such copiers and apparatus having collating and duplex capabilities.
2. Description of the Prior Art
It is well known in the prior art to provide convenience copiers: 1) with duplex capabilities; 2) with document feeders that circulate the document in a manner suitable for producing collated copies; or 3) with document inverters that present both sides of the document for copying. Examples include: 1) in relation to the first feature -- U.S. Pat. Nos. 3,318,212; 3,536,398; 3,615,129; 3,630,607; 3,645,615; 3,671,118; 3,672,765; 3,687,541; 3,697,171; 3,775,102; 3,844,653; 3,856,295; 3,862,802; 3,866,904; 3,869,202; 2) in relation to the second feature -- U.S. Pat. Nos. RE 27,976; 3,552,739; 3,556,511; 3,709,595; 3) and, in relation to the third feature -- U.S. Pat. Nos. 3,227,444; 3,416,791 and 3,675,999.
It also is known in the prior art to combine certain of the above-mentioned features in a unified structure or control. U.S. Pat. No. 3,630,607 might be considered especially relevant in its disclosure of a collating feeder on a convenience copier having duplex capabilities. Other combinations of such features are disclosed in U.S. Pat. No. 3,844,653 (a convenience copier having duplex capabilities plus a document inverting mechanism); U.S. Pat. No. 3,862,802 (a duplex copier having a document inverting mechanism useable with a sorter to produce collated copies); and "Research Disclosure Bulletin" Vol. 133, No. 13329, May 1975 (a manual approach for producing collated duplex copies without a sorter).
It is clear from the above-noted disclosures that numerous rather sophisticated structures have been developed for modern copiers to supplement their basic copying function. It is believed that such structures operate satisfactorily for their intended purposes, and many of the resulting features greatly improve the convenience and economics of the total copying operation. It will be apparent from the present invention, however that convenience copiers and duplicating apparatus can be provided with further significant and valuable features and improvements that are not avilable from, or otherwise taught by, the prior art. Typical prior art structures which are capable of producing duplex copies, for example, cannot handle two sided originals on a fully automatic basis, or have required a cumbersome and expensive sorter that complicates on-line stapling and off-set stacking. Also missing in the prior art is the facility for producing duplex collated copies in page-sequential order, or an approximation thereof, that permits finishing operations on one copy without delay waiting for other copies.